We have found significant effects of PCE on physical, neuropsychological, and behavioral development through 15 years of age. PCE was associated with higher rates of delinquency, inappropriate sexual behavior, and substance use at 15 years. This is a proposal to examine the long-term effects of prenatal cocaine exposure (PCE) in young adulthood. This cohort represents the most common pattern of PCE in non-treatment samples. Although most women who use cocaine decrease or quit their use early in pregnancy, the effects of this pattern of use have been largely unstudied. In this study, women were enrolled in their 4th prenatal month and interviewed again at the 7th month and at delivery. The birth cohort consisted of 295 mother/infant pairs; 48% were African American, 52% were Caucasian. Maternal and child assessments occurred at birth, 1, 3, 7, 10, and 15 years. At each phase, we measured maternal substance use, including cocaine/crack, alcohol, tobacco, marijuana, and other illicit drugs, demographic and psychological status, household composition, and quality of the environment. We have comprehensive child measures of growth, cognitive and neuropsychological development, achievement, psychological status, behavior, and drug use. This proposed study will define the long-term effects of PCE at 21 years of age. Young adulthood is a critical developmental stage that requires the offspring to learn and adapt to new roles and responsibilities as they develop their adult identities. It is a time that will further challenge these prenatally-exposed offspring. We will evaluate the relations between PCE and growth, cognitive and neuropsychological functioning, behavior, affect, adaptation to adult roles, and substance use. As at all earlier phases, we will carefully describe the current environment of the young adults, including their social, psychological, behavioral, occupational, educational, family, and neighborhood characteristics. The early PCE-associated problem behaviors that we have found are significant risk factors for even more serious problems in adulthood, including criminality, continued and escalating substance use, and substance use and other psychiatric disorders. We will evaluate each of these behaviors at the 21-year phase. This study is an important addition to the research on PCE: Our sample reflects the modal pattern of prenatal exposure and we have documented significant, detrimental effects of PCE that persist across time and developmental stages. As the exposed offspring continue to mature, we expect a broader range of problems in their neuropsychological, psychological, and social functioning.